Means for cleaning sewage filter beds



y 1933- w. c. LAUGHLIN ET AL MEANS FOR CLEANING SEWAGE FILTER BEDS FiledJuly 28, 1931 5 Sheets-Sheet 1 INVENTORS [William Lang/2117b y 1933- w.c. LAUGHLIN ET AL I ,919,565

MEANS FOR CLEANING SEWAG E FILTER BEDS Filed July 28', 1931 sSheets-Sheejt 2 I INVENTORJ 74 111221271 6; Laugh [in al: 01223.- /1

MMATTORNEY Jilly 1933. w. c. LAUGHLIN ET AL ,919,565

MEANS FOR CLEANING SEWAGE FILTER BEDS 137 I ll n j I; ;i

12 W HH 'MH W ll! M M 10 35 Z 40- f 4 INVENTOR' MQ'J'ATTORNEY PatentedJuly 25, l9?

WILLIAM C. LAUGHLIN, OF GARDENS, AND ,ABAM'B. ASCII, OE BOKLYN, NEWYORK, ASSIGNORS TO FILTRATION EQUIPMENT CORPORATION, OF NEW YORK,

N. '51., A CORPORATION OF DELAWARE MEANS FOR CLEAN ING- SEWAGE FILTERBEDS Application filed July 28,

Our present invention relates to sewage clarification tanks, moreparticularly to tanks of the character which are furnished with filterbeds for filtefiing out impurities; and

the invention has for its purpose and object to provide an improvedclarification tank embodying improved means for cleaning the filter bedstherein without interfering either with the filtering operations or withthe processes of sewage treatment, transpiring within the tank. v I

An object of the invention is to provide, in a sewage clarificationtank, a novel filter bed cleaning system and arrangement whereby thesolids and impurities entrapped and enmeshed in the filter bed, will beseparated from the effluent liquid that is practically free of solidsand impurities: A further object is to collect the separated solids andimpurities and to draw the same out of the tank for re-circulation orfor such other disposition as may be desired, while permitting theclarified eflluent to rise to its discharge outlet by reason of itsnatural movement towards its liquid level.

For the attainment of its objects, the invention in its evolvement hasin View the provision of a water-head for receiving the infiowing sewageliquid or material and the level of this water-head is at an elevationeflluent. Over the filter bed is arranged a traveling filter bedcleaning device having a collector chamber; and the filter bed andcleaning device are so relatively positioned that the inlet to thecollector chamber is below the level of the discharge outlet, so that byreason of the elevation of-the water-head, the liquid in the immediateterritory of the cleaning device will be forced over the inlet into thecollector chamber, whereas the liquid outside of the territory of thecleaning device will flow to the elevation necessary to pass through thedischarge outlets. According to a feature of the arrangement, the inletto the collector chamber is restricted; and it is made adjustable as toheight so that the level of this inlet may be varied with respect to thelevel of the watenhead. By virtue of this provision, the pressure andvelocity of the above the discharge outlet for the clarified 1931.Serial No. 553,528.

liquid upwardly through the filter bed in the territory of the cleaningdevice may be controlled.

More particularly, the present invention has for an object the provisionof a filter bed which includes as the filtering medium a mass of sand orsimilar filtering material. It also has for an object to provide thecleaning device with rows of projections for vention have been designedas terminal pipes or nozzles with a special view of ejecting fluid aswater and air into the filtering mass, thereby further agitating thesand of the mass and additionally churning up the same for the releaseof the dirt enmeshed therein. In the present embodiment, the rakingterminal pipes are illustrated as connected up with the pump dischargeline, so that dirty liquid from the collector chamber may itself beutilized as the means for additionally agitating the sand. 1

It is within the province of the invention to provide a clarificationtank which may have two filter beds of sand or the like, and, incorrespondence therewith, two cleaning devices with raking projectionsfor operating on the sand; and further to provide an overhead carriageor trolley which carries the two cleaning devices together with thepumps and discharge lines for discharging the dirty power unit wherebytobe self-propelled on the track rails.

By means of the carriage or .trolley, the cleaning devices are movedcontinuously along the filter beds so that the sand composing the bedsis not permitted to become sufiiciently dirty to obstruct filtration. Byreason oi the water-head, the cleaning operation may be carried out byhydraulic means in conjunction with the raking means.

In the accompanying drawings, wehave shown our invention, by way ofexample, as associated with a clarification tank and with a travelingcarriage, having respectively the general construction and arrangementillustrated and described in more detail in our companion applicationfor Letters Patent of the United States, filed August 4:, 1931, SerialNo. 555,054. The present invention is illustrated and described inbrief, as an alternative example in said companion application, butcertain novel features or" themvention herein claimed are not claimedtherein. a

With these and other objects in view, the invention consists in theconstruction and relative arrangement of parts so combined as to coactand cooperate with each other in the performance of the functions andtheaccomplishment of the results herein contemplated, and comprises in oneof its adaptations the species or preferred form illustrated in theaccompanying. drawings in which Figure 1 represents a top plan view,showing an end portion of a clarification tank provided with two sandbeds and a water.- head, and showing also the traveling carriage andcleaning devices carried thereby for operating upon the sand beds;

Fig. 2 represents a vertical sectional vdeta-il View of one of the sandbed'cleaningde vices constructed in accordance with our invention, thisview being taken on the line 2-2 of Fig. 1; 1 r Fig. 3 is a top planview of one ofthe sand bed cleaning devices;

Fig. 4 represents an end view thereof, taken on the line 4-4 of Fig. 2;and

Fig. 5 'is a diagrammatic illustration'transversely of the clarificationtank, showing the arrangement of the water-head for causing. the sewageliquid to move upwardly through the two filter beds to the eflluentdischarge outlets; v

Referring now in detail to the accompanying drawings, the sewageclarification tank is denoted in general by the reference numeral 10,and this tank in practice may consist of an elongated structure builtfrom concrete or any material that may be suitable or --approved for thepurpose. One end of the tank is provided with an inlet 11 (Fig. 5) forthe inflow of the sewage liquid. The opposite longitudinal side walls12, 12 of the tank are each provided with a launder or'trough' 13 forcarrying away the efiluent. These launders or troughs empty into a mainconduit-14 by which the efiluent is conveyed away for disposition in anymanner desired.

The interior of the tank is divided into a central chamber 15and sidechambers 16 by baffles 17 located in the upper portion of the tank andwhich terminate at their lower ends intermediate the height of the tankso as to provide in the bottom portion of the tank an open chamber 18with which the central chamber 15 and each of the side chambers 16 arein communication. The upper portion of the'chamber 15 is divided on bydownwardly extending baffles 19 which converge as they extend downwardlyin order to provide a restricted bottom feed opening 20. The inlet 11 isin direct communication with the chamber 21 between the baflies 19, andthe sewage fluid which fills thechamber 21 con 'stitutes a water-headthe level of which is elevated above the spaced outlets 22 provided inthe longitudinal sides 12 of the tank for I the discharge of theefiiuent into the launders 13. By reason of the provision of thewaterhead, a siphoning action is provided for moving the liquid upwardlythrough the side chambers 16 for discharge through the outlets 22. Thecentral chamber 15, two side chambers 16, 16 and waterhead chamber 21,all extend lengthwise of the tank, with the central chamber'lfrandwater-head 21 occuinsuch state are subjected to coagulation so that theimbibed water will be given up, need not be explained herein. Thesematters are explained at length in the companion application abovereferred to. It is sufiicient to state here that the coagulated colloidsincluding the solids of the sewage, which have a higherspecificgravitythah the water, settle downwardly to the bottom of thetank, While the lighter water, solids, and impurities rise in the sidechambers under pressure to the discharge outlets 22. The relativelyheavy matter or sludge settles onto thesloping bottom portions 23 of thetank and gradually moves to the channel 24 from where it is drawn off bya sludge pipe (notshown) or other suitable dischargingmedium. T In theupper portion of each of the side chambers 16 and below the plane of thedischarge outlets 22, is provided a filter bed.

The water and impurities rising in the side 2 i the filtering out of theimpurities takes place,

and the clear water eflluent resulting from the filteringaction risesupwardly for its disterraces charge through the outlets 22. The filterbeds consistof a mass of sand or similar material, and these beds aresupported upon suitable filter screens 26 which extend the entire lengthof the chambers 16 between the batfies l7 and longitudinal side walls12.

The apparatus for cleaning-the filter beds includes a traveling carriagewhich is designated in general by the numeral 27, and which may consistof any suitable framework capable of carrying the various parts whichmake up complete operative device for cleaning the sand beds. At itsopposite ends the carriage is provided with a pair of wheels 28 whichturn on track rails 29 provided upon the longitudinal sides 12 andinwardly oi the positions or" the e'filuent launders 13." These trackrails provide for the movement-of the carriage for the full length ofthe filter beds so that the sand can be cleaned throughout the length ofthe beds. By preference the carriage is furnished with its own powermeans, herein shown to consist oi an electric motor 30 which is mountedupon the framework and in association with the motor, a reduction gearbox 31 whereby, from the motor shaft 32, to operate the driving shaft 33at reduced speed. The driving shaft carries a gear 34 which is indriving engagement with a gear 35 mounted upon a shaft or axle 36. Ateach end of the carriage, one of thetwo track wheels is mounted on theshaft or axle 36. Two cleaning devicesare provided, one for each of thefilter beds. These cleaning devices are suspended from the carriage bymeans of suitable lE-beams 37 Inasmuch as the two cleaning devices areduplicates, a

one of them will suflice do not contact with said parts so as to'providefrictional resistance. The bottom 39 of the cleaner, in the direction ofthe length of the sand bed is such as will define a definite territoryor area of resistance for the agitation of the sand, accomplished inpart by the pressure and velocity of the liquid rising upwardly throughthe sand and in partbyraking projections 40. In the present instance,the dimension of the-cleaner, lengthwise of the bed, is increased by theprovision of an apron or plate 41 which is in alignment with the bottom39. The device, between the bottom 39 and apron 41, for the fulldimension of the device between the bafie 17 and side wall 12, isprovided with a neck or inlet opening 42 formed between the bafies 43and '44 which 1 slope towards each other as they proceed upwardly sothat the inlet will be relatively wide at the bottom where it is in opencommunication with the sand bed. The upwardly converging bafiles form atthe top of the inlet 42 a restricted feed opening 45 through which thewater passes from the inlet 42 into the interior collector chamber 46or" the clean er. Passage of the liquid through the feed opening 45 iscontrolled by a weir 47 which.

is connected with the battle 43 for relative ad= justment, upwardly anddownwardly, the particular connection indicated in the pres ent instancefor this purpose consisting in the provision of suitable elongated slots48 through which are passed threaded bolts 49 provided with wing nuts50. The upwardly extending inlet to the collector chamber is thuslocated between the tank and the apron extension which parts togetherconstitute the area or territory of resistance over the sand, whereinthe dirty water and impurities will tend under pressure to rise throughthe upwardly extending inlet and pass ovei' the weir into the interiorchamber 46.

Under the foregoing construction, it will be apparent that by reason ofthe elevation of the water-head, any adjustment ofthe weir 47 in anupward or downward direction will influence the pressure and velocity ofthe liquid upwardly through the filter bed for the area covered by thebottom 39 and apron 41. The weir, therefore, may be adjusted in theprecise position which will cause the sand between the screen 26 at thebottom of the bed and the bottom 39 and apron 41 at the top of the bed,to be kept in an agitated condition, undulating upwardly and downwardly,by the tide of liquid moving upwardly under pressure to the inlet 42.

The projections 40 provide mechanical means for raking through the sandbed and therefore stirring up the sand immediately below the inlet 42.In the present embodiment, the projections 40 consist of terminal pipesor nozzles, arranged in a row in the direction of the length of theinlet 42, that is to say, in a row transversely of the width of the sandbed. For the support of the terminal pipes, the baffle 44 is representedas provided at its upper portion with an enlargement 53 having apertures54 for receiving the pipes. T-joints 55 provided on the tops of thepipes rest upon the enlargement 53. Arranged in this way, the pipesextend downwardly' through the inlet 42 and into the sand bed. The lowerends of the pipes are close to the screen 26, so that the sand will bestirredup close to the screen. moves along the bed, the depending pipesrake through the sand, loosening and stirring it up, so that the dirtand impurities enmeshed in the sand are released or given up into thestream movlng-from the resistance area into at their lower ends,but-within the sand bed lot As the tank the inlet 42-. \The terminalpipes are closed they are provided with lateral. openings 40 for theejection of liquid or substances under pressure into the interior of thesand bed. In

this way by ejecting jets .of liquid or substance, the sand may beadditionally and thoroughly churned up from within the bedfor therelease of dirt. In-the present instance, the terminal pipes arestationary; but

direction as the cleaning device is moved along the sand bed.

Outside the territory occupied by the cleaner and its apron, the waterwhich rises from the filter bed where the sand has not been agitated, isclear and rises under the siphoning action to the discharge outlets 22.The'cleaner, it will be observed, shuts out the clear water, so thatonly the dirty water and impurities released throughthe agitation of thesand, will enter the chamber 46. The dirty water is removed from thechamber 46 by means of a centrifugal pump 56 operated by an electricmotor 57, located upon the top of the tank where itis above the level ofthe flow of clear water through the discharge openings 22. The dirtywater and impurities pumped out b the pump may be-disposed oi in anysuitable manner. In the present instance, we show a discharge pipe line58 connected with the pump and leading to a branch 59 for dischargingthe dirtv water and impurities into the water-head 21 forre-circulationythrough the clarification tank.

a One part 60 of the discharge pipe line may be connected with ahorizontal distributing manifold 61 which carries the T-joints for theterminal pipes 40. Under this arrangement, the dirty water pumped fromthe collector chamber n'iay itself be used as the medium for churning upthe sand from the interior of the bed. Suitable valves 62 and 63,furnished respectively onthe lines 59 and 60, make provision fordischarging all of the dirty water either into the water-head or intothe terminal pipes, or if desired, part of.

the dirty water into the water-head and part of it" into the terminalpipes. If desired, a

. pipe (not shown) for clean wateror other liquid may be connected withthemanifold, so that clean water may be ejected into the sand bedinstead of the dirty water from the collector chamber.

The carriage or trolley, carrying the two cleaning devices, movesforwardly and backwardly along the elongated tanks so as to intervallyclean all portions of the two sand beds from one end thereof to theother. The carriage is kept in continuous movement and the object is toclean all portions of the beds so frequently that there will be noopportu nity for the sand to become very dirty. The cleaner the beds arekept,-the cleaner the effluent will be. Owing to the provision of thewater-head, which induces a flow of the liquid into the dirty waterchamber of eachof the cleaning tanks and as well through the higherdischarge outlets 22, and the fact that each cleaning tank shuts out theclear water efiluent while defining a territory of resistance oragitation wherein the dirty water and impurities within the bed arereleased for movement with the stream into the dirty water chamber,there results a constant separa-- tion of the impurities from the bed sothat in practice the latte is practically free of solids and impurites.That part of the dirty water which is returned to the water-head is putinto re-eirculation for retreatment within the clarification tank, andthat part which is ejected into the sand bed serves as means forchurning up the sand.

It is understood that. in practice, the clean mg devices of ourinvention may be made for use 1]] connection with-circular clarificationtanks, or square clarification tanks, as well lustrate only such anembodiment as will suffiee to exhibit the character of the invention.Reservation is, therefore, made to the right and privilege of changingthe form of the details of construction or otherwise altering thearrangement of the parts without depart ing from the spiritor'scope ofthe invention or the scope of the appended claims.

We claim:

1. In combination, vided with a liquid-receiving chamber, an inletleading upwarly to the chamber for passage of liquid upwardly theretofrom the exterior bottom of the tank, said inlet including a, wall overwhich liquid escapes to fall into the chamber pipes projecting from thetank and having portions positioned for rak ing through the materialbelow the inlet and provided with orifices for jetting liquid into theraked materal to release dirt therein into the liquid destined to passupwardly through the inlet and thence over the wall into the chamber.and means carried by the tank for forcing liquid under pressure throughsaid pipes.

- 2. Filter bed cleaning means comprising," with a filter bed of sand orthe like, and

means for maintaining a pressural move ment of the liquid upwardlythrough and to a movable tank pro- I a level abovethe sand a tankmounted for I 1 a point below the maintained liquid level above thesand, means on the tank for raking the sand in the vicinity of theinlet, means for ejecting liquid into the raked sand immediately belowthe inlet for washing the dirt from the sand into the liquid destined topass over the weir into the chamber, and means for withdrawing theliquid from the chamber.

3. Filter bed cleaning means comprising, with a filter bed of sand orthe like, and means f-n' maintaining a pressural movement of liquidupwardly through and to a level above under pressure from the pump, anda series of pipes connected with the pump line and extending into thesand in the vicinity of the inlet, said pipes having discharge openingsfor ejecting liquid into the sand to thereby agitate the sand andrelease the dirt therein into the liquid destined to pass over the weirinto said chamber.

4. Means for cleaning a bed of filtering material, the same comprisingmeans for maintaining a pressural movement of liquid upwardly throughand to a level above the material, a device mounted to travel in theliquid parallel with the surface of'the bed and adapted to define overthe material a resistance area to the upward movement of the liquid, aliquid receiving chamber in the device and an upwardly extending inletleading thereto including a, wall over which liquid that rises underpr'essural movement from the resistance area will escape to fall intothe chamber, and means carried by said device for ejecting substanceinto the material within the resistance area, to agitate the materialand thereby release the dirt therein for passage with the rising liquidup through the inlet and into said chamber, said means being carried bythe device and extending into the material below said inlet.

5. Means for cleaning a bed of filtering material, the same comprisingmeans for maintaining a pressural movement of liquid upwardly throughand to a level above the material, a device mounted to travel in theliquid parallel with the surface of the bed and adapted to define overthe material a resistance area to the upward movement of the liquid, aliquid receiving chamber in the device and an upwardly extending inletleading thereto including a wallover which liquid that rises underpressural-movement from the resistance area will escape to fall into thechamber, mechanical means on said device for raking through and washingthe material in the resistance area on movement of the device,comprising tubes having liquid jetting and raking portions extendinginto the material below said inlet, and means carried by the device forforcing washing liquid under pressure through said tubes.

6. In a filter bed system including a sand bed, the combination of meansfor maintaining a pressural movement of liquid upwardly through and to alevel above the surface of the sand, a tank traveling parallel with thesurface of the sand and having a liquid'receiving chamber above itsbottom, an inlet to the chamber extending upwardly from the exteriorbottom of the tank and having a wall over which liquid escapes to fallinto the chamber at a point below the maintained liquid level above thesurface of the sand, and means carried by the tank for washing the sand,said means being effective below said inlet to release dirt into theliquid destined to rise into the inlet for collection in said chamber.

7. In a filter bed system, the combination with a filter bed, of a tanktraveling parallel with the surface of the bed and having a liquidreceiving chamber above its bottom,

an inlet to the chamber extending upwardly from the exterior bottom ofthe tank and having a wall over which liquid can flow to fall into thechamber, means for causing a tide of liquid which is to be filtered tomove upwardly through said bed and to a level substantially above theflow over said wall, and means carried by the tank for agitating andwashing the sand below the bottom of the tank, said means beingefl'ective below said inlet.

8. In a filter bed system, the combination with a tank adapted to bemoved parallel with the surface of a sand bed, of an inlet channelintermediate the length of the tank extending upwardly from the bottomthereof for directing liquid rising upwardly from the bed into theinterior of the tank, a weir adjustably associated with the channel andover which rising liquid will flow to fall into the interior of thetank, and means carried by the tank for washing the sand bed below saidinlet channel.

WILLIAM C. LAUGHLIN. ABRAHAM-B. A'SCH.

